SmallCaliberCentral

Did a search and read most of the posts with no epiphany.

I am a experienced reloader but new to the 204 Ruger cartridge.

Gun: Cooper in 204 Ruger
Scope: Zeiss 6.5-20
Load data: Winchester case; Wolf SRM, CCR-BR/Rem 7 1/2/Fed GMM primers/Have Not tried other Mag primers yet;
Powders IMR 8208 XBR and BenchMark;
Powder weight 29.3 of 8208 and 26.6 of BenchaMark
Rest: Sinclair with rear bags
Shooting table: Concrete
Using wind flags and range is 100 yards

I am getting reasonable groups (.7 and lower) but I am finding the velocity spreads to be much larger than hoped for - in the order of 70 fps.

Any experience with these ES spread and range results to verify an improvement?

Are those velocity spreads between the loads and mixed primers, or the average of spread with loads and the same primer, in each group ? I have had some groups/loads show a larger velocity spread than I thought should, but that load grouped so good, I just did nto worry about it. If it shot little teeny groups, even tho one FPS was 3400 and then next 3460, I really did not care. Maybe I am not too picky. Anyway just my thought. Bill K

I'm with Bill K., I shoot a 204 Ruger in Cooper Phoenix also and I shoot 27.5 grains 8208 XBR but get well under .430 groups consistently and many 5 shot groups .315 or less. I see 40/50 FPS extreme spreads but am happy with the accuracy. I've found that unless I'm shooting 900-1000 yards I'm really not to concerned with extreme spreads , I look for consistent accuracy. I'

I agree with Bill K and FastPPC; look at how it groups. I've good SD and ES and lousy groups and then; vice-versa.

HTH

The large ES's were with the same load, cases, and primers. I haven't tried 27.5 of 8208 so I might give that a try. I'm looking at using the 204 for prairie dog hunting so the ES's should cause vertical dispersion at distance - at least that is my experience with shooting other guns in NRA mid and long range matches.

Groups seem better with 26.6 of Benchmark for me.

Thanks guys for the help.

I don't try to shoot 'long range' with my 204, so like the others I just look for good precision. Nevertheless, maybe see if annealing the brass helps? Sometimes high ES indicates variable neck tension, or anyway it _has_ for me, on occasion.